PURPOSE: To enable to collect the liquid filtrate with good efficency, by providing the nozzle jetting the liquid into a screen and rotating it, in the liquid processor provided with a cylindrical screen.

CONSTITUTION: A header 14 contg. a sprinkler etc. is provided in the screen 6 movably, and the spray pipe 11 is linked to the header so that the spray liquid can be fed to the header 14. This header 14 is fitted with the arms 15 projected radially to the screen 6 and wide angle spray nozzles 16 are fitted to the tip of the arms 15. In the wide-angle spray nozzles, the jet direction of spray nozzle is taken almost at tangential direction of rotating circumference, and the header 14 is rotated with the reaction of spray liquid jet from the nozzles 16. Thus, the liquid filtrate 13 flows in from the whole surface of the screen 6 to increase the filtration efficiency.